Penryn heat

Discussion in 'MacBook Pro' started by nightcat, Jul 2, 2008.

  1. nightcat macrumors newbie

    May 17, 2008

    I bought a MBP(Penryn, 2.5Ghz) last week.
    It runs smooth and beautiful. It works perfect. I might only dream about better battery, but beside of that, I'm absolutely happy with it.

    Except the heat.

    I'm a dev, so I like the idea of having three platforms, I installed ubuntu and windows on it using boot camp. It took me a while, but I succeeded!

    Initially, MBP went crazy hot on MacOS, and it cooled down after 10.5.4 update.
    On Ubuntu I can control the CPU throttling and fan speed (well, it's done automatically) so it works like a dream.

    The problem is on Windows. I installed Windows XP SP3 with bootcamp 2.1 and the temperature is crazy high.

    It's up to 45-50 celsius on CPU1 and CPU2 without any load. And it goes up to 70 celsius on NVIDIA GPU without any app runned at all.
    It makes both sides (the speakers area) very hot and I had to manually launch fans through input remapper because otherwise the fans were off.

    Even with the fans 100% on, the temparature is just below 40 celsius on CPU's and around 60 celsius on GPU but the laptop is not hot anymore.

    It seems that the main source of heat is NVIDIA GPU. Can I do anything about it?
    I'm afraid to launch any movie, game or 3d app if it goes that hot without it :(
  2. lordthistle macrumors 6502

    Feb 29, 2008
    I would say it's normal. As you already know, when temps are too high the notebook shuts down by itself. The aluminum case, the low thickness, and the choice to keep fans' speeds down as long as possible result in a very high temperature. In some cases it bothers me and I have to stop working for a while. In this case a plastic case helps.

    The problem with the new MBPs is represented by the commercial ads and by the reviews written by mac-zealots (way too many). All of them describe the new Penryn processors as refrigerated and cold units.

    And you are right: the gpu produces a lot of heat. My MBPs used to reach unbelievable temperatures when importing and scaling pictures in Aperture. Aperture uses the gpu.

    -- thistle
  3. nightcat thread starter macrumors newbie

    May 17, 2008
    well, but this will not help me.

    If it was possible to cool it down on MacOS, I hope there's a way to reduce the heat on Windows XP.

    Maybe MacOS just throttles GPU speed while Windows keeps it on full speed all the time?

    Also, I read somewhere that on Windows the fan goes on only when the temperature is reaching the maximum, and before that it stays off.

    Ih hope it's somehow solvable :/
  4. ManWithhat macrumors regular

    Jun 24, 2008
    This may be wrong, but from what I was told, on PCs the throttling is controlled by the BIOS via the motherboard. Perhaps OSX, the system, is controlling the throttling. It'd explain it.
  5. Beau10 macrumors 6502a

    Apr 6, 2008
    Downtown San Diego

    I'm a dev too (.NET) and have a 2.4 Penryn... I use Fusion. Granted things run about 50% speed, but the flexibility of VMs for different environment setups is awesome + power management is still under OSX control. I use the Fan Control app to set a fan speed gradient, much better than stock and SMC Fan Control.

    That said these temps are normal and approximately what I see at idle. Really running my machine hard, like during a compilation, I can see temps all the way up to the low 70s. Most of the time when working during the day it hovers in the mid 50s to low 60s.

    There's a recent thread about someone reapplying thermal paste and how it drastically lowered his temps, like close to 10 degrees. That's a decent amount of work as you have to remove the logic board to get at the heat sink, but it might be something worth doing say if you plan on replacing the hard drive.

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